package wang.lxl.remoteexecute;

/**
 * @Author lixilin
 * @Date 2021/4/24 9:07
 * @Description byte数组处理工具
 */
public class ByteUtiles {
    private ByteUtiles() {

    }
    public static int bytes2int(byte[] b, int start, int len) {
        int sum =0;
        int end = start+len;
        for (int i = start; i < end; i++) {
            int n = ((int)b[i]) & 0xff;
            n <<= (--len) * 8;
            sum = n +sum;
        }
        return sum;
    }

    public static byte[] int2Bytes(int value, int len) {
        byte[] b = new byte[len];
        for (int i = 0; i < len; i++) {
            b[len - i - 1] = (byte) ((value >> 8 * i) & 0xff);

        }
        return b;
    }

    public static String bytes2String(byte[] b, int start, int len) {
        return new String(b, start, len);
    }

    public static byte[] string2Bytes(String string) {
        return string.getBytes();
    }

    public static byte[] bytesReplace(byte[] originalBytes, int offset, int len, byte[] replaceBytes) {
        byte[] newBytes = new byte[originalBytes.length + (replaceBytes.length - len)];
        System.arraycopy(originalBytes,0,newBytes,0,offset);
        System.arraycopy(replaceBytes,0,newBytes,offset,replaceBytes.length);
        System.arraycopy(originalBytes,offset+len,newBytes,offset+replaceBytes.length,
                originalBytes.length -offset-len);
        return newBytes;
    }
}
